Entanglement of coherent superposition of photon-subtraction squeezed vacuum  

作　　者：Cun-Jin Liu Wei Ye Wei-Dong Zhou Hao-Liang Zhang Jie-Hui Huang Li-Yun Hu 

机构地区：[1]Center for Quantum Science and Technology, Jiangxi Normal University, Nanchang 330022, China

出　　处：《Frontiers of physics》2017年第5期159-169,共11页物理学前沿（英文版）

摘　　要：A new kind of non-Gaussian quantum state is introduced by applying nonlocal coherent superposition （τa＋ sb）^m of photon subtraction to two single-mode squeezed vacuum states, and the properties of entanglement are investigated according to the degree of entanglement and the average fidelity of quantum teleportation. The state can be seen as a single-variable Hermitian polynomial excited squeezed vacuum state, and its normalization factor is related to the Legendre polynomial. It is shown that, for τ = s, the maximum fidelity can be achieved, even over the classical limit （1/2）, only for even- order operation m and equivalent squeezing parameters in a certain region. However, the maximum entanglement can be achieved for squeezing parameters with a π phase difference. These indicate that the optimal realizations of fidelity and entanglement could be different from one another. In addition, the parameter τ/s has an obvious effect on entanglement and fidelity.A new kind of non-Gaussian quantum state is introduced by applying nonlocal coherent superposition （τa＋ sb）^m of photon subtraction to two single-mode squeezed vacuum states, and the properties of entanglement are investigated according to the degree of entanglement and the average fidelity of quantum teleportation. The state can be seen as a single-variable Hermitian polynomial excited squeezed vacuum state, and its normalization factor is related to the Legendre polynomial. It is shown that, for τ = s, the maximum fidelity can be achieved, even over the classical limit （1/2）, only for even- order operation m and equivalent squeezing parameters in a certain region. However, the maximum entanglement can be achieved for squeezing parameters with a π phase difference. These indicate that the optimal realizations of fidelity and entanglement could be different from one another. In addition, the parameter τ/s has an obvious effect on entanglement and fidelity.

关 键 词：non-Gaussian operation quantum entanglement squeezed state 

分 类 号：O431.2[机械工程—光学工程] O436.1[理学—光学]